Process and apparatus for koshering container lids
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation-in-part application of application Ser. No. 07/550,298, filed July 9, 1990. Said application Ser. No. 07/550,298 is a continuation-in-part of application Ser. No. 07/348,803 filed 08/08/88, which is in turn a continuation-in-part of application Ser. No. 07/131,291, filed 12/08/87, now U.S. Pat. No. 4,830,675, which is a continuation of application Ser. No. 06/872,016 filed 06/09/86, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to the processing of manufactured metallic containers and, in particular to a process and apparatus for koshering the lids that form part of metallic containers. In the above-identified, commonly-owned, copending application, there is disclosed an apparatus for koshering metallic containers before the top and bottom closure-lids have been placed thereon. The present invention is directed to an apparatus and a process for achieving the koshering of these top and bottom closure-lids. 
     In commonly-owned, copending application Ser. No. 07/348,803, filed on May 8, 1989, there is disclosed another oven by which the flame-treating of these metallic containers may be carried out. 
     The strict Jewish dietary laws by which it is determined that foods are kosher require total abstinence from certain foods, prohibit the mixing of certain types of food on a single plate or at a single meal, and also prescribe the manner in which an animal, in order to be considered kosher, must be raised, butchered, and cooked. For example, according to Mosaic Law, certain foods such as pork products and shrimp are inherently not kosher and cannot be prepared to render them kosher. It is also a requirement of the dietary laws that meat dishes and dairy dishes cannot be consumed together, so that otherwise kosher foods, if improperly combined in a single meal will render the meal non-kosher even though the individual components themselves are prepared according to the laws of kosher. 
     When a vessel, such as a cooking pot, is used to prepare a meat dish, and must thereafter be used to prepare a dairy dish, the vessel must be cleaned thoroughly enough to remove all vestiges of the previously prepared meat dish, such as by the use of boiling water, steam, or flame drying. To my knowledge, there has been no practical method developed to date to adapt such a koshering process to large-volume containers, such as 55 gallon drums. If, for example, the food to be stored is &#34;dairy&#34; in nature, the presence of any contaminant traceable back to a &#34;meat&#34; origin may destroy the kosher character of the food. In like fashion, any &#34;non-kosher&#34; contaminant may also produce the same result. 
     Problems can then arise when, after food has been prepared in a kosher manner, it is stored in such a way that the storage vessel becomes a vehicle for contaminants which, while not adulterating the food in a medically harmful sense may still contribute contaminants of a character sufficient to destroy the kosher integrity of the food. 
     As an example, certain metallic containers, such as cans or drums used for the bulk storage and transportation of foods may, during the manufacturing process, may come in contact with, and be coated with a thin film of oil or grease, the presence of which in an otherwise kosher food may destroy the integrity of the koshering process. 
     Foods prepared in accordance with the dietary laws are certified as kosher by one trained to observe the entire manufacturing process and determine whether the method of preparing the food and the individual ingredients are consistent with the practice and observance of the dietary laws. In much the same manner, the same determination must be made with respect to the preparation of packaging for the food so prepared. 
     U.S. Pat. Nos. 4,830,675 and 4,906,301--Skolnik, which patents are incorporated by reference herein, disclose a method for achieving the koshering of the above-mentioned drums, in which the surfaces of the drums are subjected to flame-treatment for burning off any residue of oils, fats, and the like. 
     SUMMARY OF THE INVENTION 
     It is the primary objective of the present invention to provide a process and an oven-apparatus by which the flame-treatment of drum-lids is carried out in a manner that ensures the koshering of the lids. 
     It is another objective of the present invention to provide such a flame-treating oven-apparatus that flame-treats a series of drum-lids transported therethrough via a conveyer system. 
     It is another objective of the present invention to provide such an oven-apparatus at one end of a conventional drum-lid bath, so that immediately after each lid has been washed clean by the drum-lid bath, it enters into the oven-apparatus of the invention for the flame-treatment thereof. 
     The oven-apparatus of the invention has a substantially hollow interior through which are conveyed the lids after having passed through the water bath, with the lids being conveyed through the hollow interior in a semicircular or arcuate path, with the inlet or entrance being positioned directly in-line with the exit of a conventional hot-water bath for initially washing the lids clean. The same conveyer system that conveys the series of lids through the water-bath is also used for conveying the lids through the flame-treating oven apparatus. After having passed through the oven-apparatus of the invention, the flame-treated lids are conveyed in the conventional manner substantially parallel to but in the opposite direction by which they were conveyed through the water bath. Within the hollow interior of the oven-apparatus, there are provided a pair of flame-burners. One flame-burner is mounted at a first corner of the housing of the oven-apparatus at an acute degree angle with respect the center line of the main housing. The second flame-burner is positioned at an opposite corner also at an acute angle with respect to the center line of the main housing but with an opposite sense as compared with the first burner. The first burner&#39;s flames flame-treat the first surface-face of each lid transported through the oven-apparatus, while the second burner flame-treats the second, opposite surface-face at the same time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood with reference to the accompanying drawing, wherein: 
     FIG. 1 is an isometric view of the oven-apparatus of the invention for carrying out the flame-treatment of container-lids, and also showing a conventional hot-water bath at the exit of which is mounted the oven-apparatus of the invention; 
     FIG. 2 is an isometric view showing the interior of the oven-apparatus where each container-lid is flame-treated according to the invention, as each lid is being conveyed through the oven-apparatus along a semicircular or arcuate path therethrough; and 
     FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 1. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While use of the oven-apparatus of the invention disclosed herein may be extended to container-lids of varying sizes and configurations, a preferred use of the presently-described oven-apparatus is directed primarily to relatively large containers, such as steel drums having a capacity of about 55 gallons. Such drums are typically cylindrical in shape and have lids which may be either strapped, crimped, or otherwise attached to close off the drum. Access to the drum may thereafter be had by removing the lid, or through a hole or port formed in the lid. 
     Referring to figures, there is shown the oven-apparatus 10 of the invention used in flame-treating container or drum lids. 12. The apparatus 10 includes a main housing 14 defining a pair of parallel side walls 16,16&#39;, an upper wall 18, a rear wall 20, a front wall 22, and a bottom wall 23, all made of heat-insulating material. The front wall 22 defines an opening or entrance or a pair of openings for defining ingress and egress of the conveyed lids through which are conveyed the lids 12 for flame-treatment in the oven 10. The main housing 14 is supported at its rear by a pair of legs 13 which rest on the floor, so that the oven 10 proper is elevated enough above floor or ground level so as to align the opening or openings of the front wall 22 along the path of conveyed lids exiting from a lid-bath, described below in greater detail. The front of the main housing may be directly mounted to the rear of a lid-bath via cross-brace a mounting frame 15. The interior of the main housing is ventilated via a ventilator 19. 
     The oven 10 is positioned in close juxtaposition to a conventional bath 30, which bath may be a hot-water bath, a bath containing liquid rust inhibitor, or may be a phosphatizing bath. In the example shown in FIG. 1, the bath 30 is a hot-water bath which has a main tank 32 filled with water that is about 110-120 degrees F. It is, of course, within the scope and purview of the invention to place the oven 10 directly at the exit of one of the other baths just above-mentioned, which other conventional baths also have similar conveying systems as that shown in the FIGS. 1-3 and discussed below in greater. 
     A first or in-feeding portion of a conveying system 34 conveys the series of lids to be washed through the water-bath. This conveyer system includes a conveyer belt or chain 36 from which hang a series of spaced-apart hooks 38 for movement along with the conveyer belt 36, which individually support and suspend a container-lid therefrom, in the conventional manner. The conveyer system has its intermediate portion substantially low enough so that the suspended lids may pass through the water-bath 30, as seen in FIG. 1. The conveyer system 34 thereafter rises at the portion indicated by reference numeral 36&#39; in FIG. 1 in order to raise the lids from the water bath when reaching the end of the bath. Thereafter, the conveyer system 34 turns about 180 degrees at its transition-portion 36&#34; seen in FIG. 3. After having turned a full 180 degrees, the return-portion 37 of the conveyer system returns the washed lids back to a storage area, for subsequent handling and for subsequent placement onto a drum. The return-portion 37 is a linear, raised section that spaces the lids above and laterally away of the water-bath 32 during the return-trip of the lids 12. 
     The above-described water bath and conveyer system therefor is conventional. The oven 10 of the invention utilizes the straight, end-portion of the section 36&#39; and the straight end-portion of the return section 37, and the transition-portion or section 36&#34; for conveying the washed lids into the interior thereof and out of the interior thereof, such that these above-mentioned portions of the conveyer are received within the hollow interior of the oven, as clearly shown in FIG. 3. During the passage of the lids through the oven 10, each lid is flame-treated such that all exposed, exterior surfaces of each lid are exposed to and contacted by a flame for achieving the flame-treating, koshering of each lid. 
     Referring to FIG. 3, there is shown a pair of flame-burners 40, 42, mounted in the interior of the main housing 14 at the two corners thereof formed by the rear wall 18 and the two side walls 16, 16&#39;. Each burner 40, 42 during the flame-treatment of a series of conveyed lids is continuously operated, and in the preferred embodiment is a one-million BTU, conventional, gas-burner, and may be that manufactured by Eclipse Manufacturing Company, model JIB. The burners are supplied gas via a common tubing 44 from a source-pipe 46. The gas burners 40, 42 are mounted at a respective corner via a mounting plate assembly 40&#39;, 42&#39;, respectively. In the preferred embodiment, each mounting assembly is affixed to the rear wall 18 and a respective side wall 16, 16&#39; via an angle-bracket 46, 48, respectively, which mounts the respective gas burner directly. Since each angle-bracket 46, 48 is spanned across the rear wall and a side wall, it forms an acute angle with respect to these walls, such that each gas burner 40, 42 faces in the direction of transition-portion 36&#34; of the conveyer system, so that as the lids 12 are conveyed therepast, the flames from the gas-burners will contact all of the surfaces of each lid. That is, the flames from the burner 40 will contact the surface face of each lid facing it, as seen in FIG. 3, while the flames from the burner 42 will contact the surface of each lid facing it. The angle-bracket 46 or 48 is mounted below the vertical lever of the transition-section 36&#34; of the conveyer system, so each burner 40, 42 is also mounted angularly upwardly by a cross-piece 50 seen in FIG. 2. Each cross-piece 50 is connected to a respective angle-bracket 46, 48, whereby the longitudinal axis of each gas-burner forms not only acute angle (preferably of 45 degrees) with respect to the rear wall 18, but also forms an acute angle with respect to the bottom wall 23, as seen in FIG. 2. 
     As can be seen in FIG. 3, each burner is preferably mounted on a rearward section of the respective angle-bracket, so that the flames from each burner are directed to the apex or center area of the transition-portion 36&#34;. Preferably, for maximum flame-treating effect, the longitudinal axis of each burner is an approximate tangient to the curved transition-portion 36&#34;, although this is not a requirement. By directing the flames from the gas burners to the apex of the transition section 36&#34;, it is ensured that all surfaces of the lid are flame-treated. In addition, since the flames from each burner form an expanding cone-shape, as seen in FIG. 3, it is not only ensured that each surface face of the each lid is contacted by flames, but it is also ensured that the circumferential edge surface of each lid is also contacted by the flames. This is achieved by the provision of gas burners that produce flames that will more than encompass the full lid, so that the flames contact the full circumference of the rim of each lid, from each side of the lid, especially owing to the relatively thin nature of the lid. 
     While a specific embodiment of the invention has been shown and described, it is to be understood that numerous changes and modifications may be made therein without departing from the scope, spirit and intent of the invention as set forth in the appended claims.